1. Field of the Invention
This invention relates generally to memory devices, and more particularly to security memory devices that provide protection from unauthorized duplication.
2. Description of the Related Art
Computer systems, such as desktops, notebooks, and servers, typically use flash memories to store the basic input output system (BIOS), which boots the computer system during power up. Flash memories are also used to install operating systems and provide basic input/output routines for many computer systems. Thus, flash memories have an important role in all computer systems today.
Flash memories also have an important role in the operation of small devices, such as mobile phones, personal digital assistants (PDAs), set-top boxes, and game machines. In such computer systems, flash memories provide almost all of the applications executed on the computer systems. That is, almost all the software that is run on small devices is stored in flash memories.
Unfortunately, the software contents of flash memories is often vulnerable to unauthorized duplication. Such unauthorized copied software is commonly distributed on a wide-scale basis over the Internet and via flash memories and recordable CD-ROMs. As a result, software developers lose billions of dollars each year from such unauthorized copying and distribution.
Software developers commonly use a variety of different forms of copy protection to prevent unauthorized copying and using of their products. One of the most robust methods involves reverse engineering. When a chip is reverse engineered, all the individual circuits that make up the chip are identified, and the source code is reverse engineered into design models or specifications.
In view of the foregoing, there is a need for systems and methods for protecting flash memory from unauthorized duplication. The systems should discourage unauthorized coping of flash memory content by erasing or otherwise rendering the flash memory content unusable.